Broccoli Cheese Soup

1 lg onion sautéed in 1 stick of butter.
2 cans chicken broth
2 cans cream of mushroom soup,
12 ounce package of shredded cheese of choice
(I use Kraft's Fancy Blend - cheddar, American, Monterey Jack),
2 cans milk
Broccoli - parboil first

Mix in stock pot & simmer. Do not boil. Season with salt and pepper.